Apparatus for collecting and discharging metal powders



May 19, 1953" H. A. GoLwYNNEl APPARATUS FOR COLLECTING AND DISCHARGING METAL POWDERS Filed sept. 29, 1949 V O o ATTORNEYS Patented May 19, 1953 UNITED STATES. PATENT oFFicE APPARATUS FOR COLLECTING AND DISCHARGING METAL POWDERS Henry AfGolwynne, New York, -NQY. Application September 29, 1949, Serial No. 118,626

9 Claims. (Cl. 18S-85) This invention relates to the production of metal powders and has for its object more particularly certain improvements in apparatus for collecting and discharging metal pow-ders.

Certain metal powders tend easily to combine with oxygen even at comparatively'low temperatures, sometimes to the extent of being subject to spontaneous combustion. This is true particularly of such metals as magnesium and of 'some finely divided non-metal particles. The production of metal powders such as magnesium is a definite hazard. Innumerable res andV explo- 'sions have occurred,` often doing a great deal of damage. Workmen are often reluctant to work in metal powder producing plants and particularly in those sections of a plant where such res and explosions are most apt to occur.

One of those sections is the place where the magnesium powder, for example, is collected and discharged into other containers. In the production of such powder by atomizing a fine stream of molten ymagnesium in an inert or nonreactive atmosphere, the powder-gas is subjected to a separation step resulting in the-deposition of the powder. Such a procedure is disclosed in. my copending applications, Serial Nos. 118,- 621 and 118,622,v filed September 29, 1949, simultaneously herewith. The magnesium powder is generally permitted to accumulate at the bottom of the separator or a collector associated therewith, from which the powder is gradually withdrawn; but not inamounts sumcient to permit air to seep into the separator or collector. In other words, enough powder is retained at and above the discharge outlet to act as a seal against ingress of air. In spite of this precaution, h owever, magnesium powder flowing from the outlet sometimes catches on lire. This scares the operator, who is then apt to jumpr back or even run away. As he does so he lets go of the closure member at the outlet, thus exposing more powder to the fire which can promptly reach explosive proportions. Air'also seeps into the collector and separator,l thus converting the inert or non-reactive atmosphere of the system into a highly reactive one. I f

My investigations have led to the discovery that certain improvements in apparatus for collecting and discharging such finely divided materials make it possible to conduct the operation in comparative safety. Elven if. a `rire should occureat the discharge outlet; the improvements are such that the apparatus may be readily operated to close itself, even to close itself automatically, and thus to' prevent further amounts 2 of the powder from coming into'contact with the re and air and thereby to prevent the fire from spreading. f

In accordance with the invention, the apparatus for collecting and discharging finely divided material, such as metal powder, includes a dis-f charge conduit for the material communicating with a collector; a relief chamber connects 'the discharge conduit near its outlet; a closure meme4 ber is provided at the outlet to open and close the same, the closure member being adapted t0. force adjacent :material at the outlet into the relief chamber instead of back into the conduit and collector to facilitate closing of the discharge outlet. The closure member is preferably provided with self-clo'sing means to'cause it to move to its closed position automatically when not in USB.

In a present practice the closure memberl ishinged to a fixed support so that the closure member may be raised and lowered angularly to close andV `openv the discharge outlet. The hinged closure member is advantageously in the form of a chute to facilitate discharge of the powder intoacontainer. K 1

If an operator moves the closure member man.- ually to its open positionto discharge some of the collected magnesium powder, for example, and a fire should suddenly occur, he may promptly move the closure member back into its closed position. To facilitate this closing movement, magnesium powder directly adjacent'or above the closure member is easily pushed into the relief chamber. In the absence of the relief chamber, enough pressure would have to be applied to the closure'member to push not only that portion of the magnesium powder but all of the other powder behind it backwardly inthe conduit and-collector. This would only add to the operators diiculties, because the closure member might not completely reach its closed position. A substantial amount of the magnesium powder would then remain exposed to the air and therefore subject to burning or combustion. The use of the relief chamber, however, greatly facilitates closing of the 'closure member since very little pressure orv force is required to shove that portion of the metal powder into the chamber. v v l On the other hand, if the closure member is provided with the self-closing means, the operator may,v as hev sometimes does, instinctively vlet go of the closure member in his fright, the 'closure member nevertheless closes automaticallywithout any intervention on his` part.`

connected to the hopper for the discharge of finely-divided material therefrom, said discharge conduit having its lower portion connected to said container a substantial distance below the closed end thereof for the feeding of material discharged from the hopper laterally into said container, the upper portion of said container forming a relief chamber and the lower portion thereof forming a continuation of the discharge conduit, the bottom of the chamber having an opening forming an outlet for material discharged from the hopper through said discharge conduit, and a closure member for said outlet, the closure member being so mounted that on moving to its closed position it moves in an upward direction against the finely-divided material being discharged from the outlet, whereby the lifting effect exerted on the finely-divided material by the closure member when moving to its closed position will force nely-divided material adjacent the outlet upwardly into said relief chamber rather than backwardly through the discharge conduit towards the hopper.

2. In apparatus for collecting and discharging finely-divided material as set forth in claim 1, the further improvement in which the closure member is provided with self-closing means to cause it to move to its closed positionvvhen not in use.

3. In apparatus for collecting and discharging finely-divided material as set forth in claim 1, the further improvement in which the closure member is in the form of a hinged chute.

4. In apparatus for collecting and discharging finely-divided material as set forth in claim 3, the further improvement in which the chute has an outer collar at its top fitting longitudinally around the lower end of the container, the upper end of the collar is secured to the lower end of a flexible sleeve loosely surrounding the container, and the upper end of the exible sleeve is secured to the container, so that when the chute is moved upwardly and downwardly the flexible sleeve yields sufficiently to permit the discharge outlet to `be closed and opened.

5. In apparatus for collecting and discharging finely-divided material as set forth in claim 4, the further improvement in which the closure member is provided with self-closing means to cause it to move to its closed position automatically when not in use.

6. In apparatus for collecting and discharging finely-divided material as set forth in claim 5, the further improvement in which the means for closing the discharge outlet when the chute is not in use includes a spring-tensioning device secured at its lower end to the chute and at its upper end to a fixed support.

7. Apparatus for discharging material subject to spontaneous combustion which comprises a container closed at its upper end, a discharge conduit for discharged material, said discharge conduit having its lower portion connected to said container a substantial distance below the closed end thereof for feeding discharged material laterally into said container, the upper portion of said container forming a relief chamber and the lower portion thereof forming a continuation of the discharge conduit, the bott-om of the chamber having an opening forming an outlet for material discharged through said discharge conduit, and a closure member for said outlet, the closure member being so mounted that on moving to its closed position it moves in an upward direction again-st the material being discharged from said Ioutlet.

8. Apparatus for receiving and discharging material as set forth in claim 7 in which the closure member is in the form of a hinged chute.

9. Apparatus for receiving and discharging material as set forth in claim 8 in which the chute has an outer collar at its top tting longitudinally around the lower end of the container, the upper end of the collar is secured to the lower end of a exible sleeve loosely surrounding the container, and the upper end of the flexible sleeve is secured to the container, so that when the chute is moved upwardly and downwardly Athe flexible sleeve yields sufliciently to permit the discharge outlet to be closed and opened.

HENRY A. GOLWYNNE.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,001,543 McDonald Aug. 22, 1911 1,024,297 Thompson Apr. 23, 191'2 1,037,167 Paine Aug. 27, 1912 1,125,032 Goodell Jan. 12, 1915 1,233,246 Kerlin July l0, 1917 1,245,366 Mathesius Nov. 6, 1917 1,735,298 Pfeifer Nov. 12, 1929 1,954,352 Dornbrook et al. Apr. 10, 1934 2,456,044 Biermann Dec. 14, 1948 FOREIGN PATENTS Number Country Date 221,218 Great Britain May 21, 1925 

